docs: def encrypt_attribute(attribute_name, attribute, encryption_key, algorithm):
      # type: (Text, dynamodb_types.RAW_ATTRIBUTE, DelegatedKey, Text) -> dynamodb_types.BINARY_ATTRIBUTE
      """Encrypt a single DynamoDB attribute.
  
      :param str attribute_name: DynamoDB attribute name
      :param dict attribute: Plaintext DynamoDB attribute
      :param DelegatedKey encryption_key: DelegatedKey to use to encrypt the attribute
      :param str algorithm: Encryption algorithm descriptor (passed to encryption_key as algorithm)
      :returns: Encrypted DynamoDB binary attribute
      :rtype: dict
      """
      serialized_attribute = serialize_attribute(attribute)
      encrypted_attribute = encryption_key.encrypt(
          algorithm=algorithm, name=attribute_name, plaintext=serialized_attribute
      )
      return {Tag.BINARY.dynamodb_tag: encrypted_attribute}